Description

Common barberry is an upright and arching shrub that can reach 10 feet in height. The branches are grooved, gray and glabroussmooth; free from hairs, and usually have groupings of three spines (or as few as one) along them. The spines are usually rounded, but can rarely be flattened. The dull green leaves are obovatean egg shaped leaf with the narrower end at the base to obovate-oblong and have finely serrate margins (occasionally the serrations are more prominent). The leaves are alternate or fascicled and are 0.75-2.0 inches in length. The bright yellow flowers of Berberis vulgaris have an unpleasant smell. They are arranged in pendant racemes that can be 1-2 inches long with 10 to 20 flowers on each. These flowers usually appear from late May into June. The fruit are ellipsoid in shape, red in color and are around 0.4 inches long. They contain 1-3 small, black seeds.

Habitat

Berberis vulgaris is found sporadically in New England, usually in open-canopied forests and sometimes along roads. It is also very successful in calcareous soilssoils formed from the crushed up and decayed shells and bones of sea creatures.

History and Introduction

Berberis vulgaris was introduced in the United States as early as the 17th century when early settlers planted it for producing jam from its fruits, yellow dye, and thorn hedges. It naturalized over a large area of the northeast. Eventually, it was recognized as being an alternate host for wheat rust, Puccinia graminis. As a consequence a huge effort was made to eradicate the plant in the early 20th century, and this effort was rather successful. 

Berberis vulgaris is now found sporadically across the landscape: it appears to have been eradicated in some areas, while it persists quite abundantly in others, especially near the coast.

Threats

Though common barberry is not very common on the landscape in most places, there is a risk that it could once again become a serious pest. The fact that it is an alternate host for wheat rust prevents its sale (seeds and plants) in many states.

Dispersal Methods

The fruit of Berberis vulgaris are dispersed by birds. Small mammals can also contribute to their dispersal. It can also spread when branches come in contact with the soil, producing new plants.

Control

Mechanical

Small infestations can be controlled manually by digging and removing the root system. All roots must be removed to prevent resprouting. In early spring, use a hoe, weed wrench, or mattock to uproot the entire bush and associated roots. Use gloves to help protect hands from the spines, once large shrubs have been removed from fields, regular mowing helps prevent reestablishment. 

Chemical

It can be effectively controlled using any of several readily available general use herbicides such as glyphosatea widely used herbicide that can kill certain weeds and grasses, it works by blocking an enzyme essential for plant growth or triclopyrherbicide used to control both broadleaf and woody plants. Follow label and state requirements.